Vitamin D plays potential role in modulating our body’s defense system. Vitamin D receptors belong to the family of nuclear receptors, and therefore almost every tissue of our body is influenced by vitamin D.

Integration of vitamin D with its receptors on fighter cells arms body’s defense system to successfully win the battle with foreign invaders; bacteria, virus, allergens, toxins or intestinal worms. It is noted that vitamin D deficient children are more prone to childhood infections, allergic episodes and autoimmune disorders.

Vitamin D being a form of steroid also has steroid sparing effect in cases of asthma; an attribute that improves lung functions and diminish allergic reactions. Nevertheless, effect of vitamin D supplementation on allergies is not only dose dependent but also varies with the age at which child receives it.

The study published in Pediatrics, Nov 2012 issue showed that the infants of mothers who had suboptimal vitamin D levels during pregnancy were at increased risk of atopic eczema.

Yet other studies have shown high level of vitamin D in mother to be associated with less wheezing in their infants. High dose supplementation of vitamin D during pregnancy thereby gained favor.Maternal vitamin D levels of more than 30 ng/ml increase the risk of atopic eczema and asthma. This is further emphasized in “Cord blood 25-hydroxyvitamin D levels are associated with aeroallergen sensitization in children...” J Allergy Clin Immunol . Nov’ 2011.

High blood levels of vitamin D are also linked with increased risk of food allergy: The perspectives of prevention using vitamin D; Curr Opin Allergy Clin Immunol 2013

The role of vitamin D in prevention of allergies is complex and at the moment not clear enough for precise clinical implementation as a form of prevention or treatment. Yet optimal vitamin D intake cannot be overemphasized.

Low vitamin D content is very common, especially in children from affluent and western society. This is because 80% of vitamin D in our body is produced by the effect of sunlight on the skin. But, in modern times, outdoor activities have been reduced to minimum for the fear of UV rays exposure in relation to skin cancer.